Step-by-step electric motor



UCL 5, 1953 w. LoHs ET AL STEP-BY-STEP ELECTRIC MOTOR Filed Nov. 30,1951 Patented Oct. 6, 1953 STEP-BY-ISTEP ELECTRIC MOTOR Willy iIiohs,Berlin-'Siemensstad`t, and Friedrich Sommer, Berlin-Nikolassee, Germany,assignors to Siemens & Halske Aktiengesellschaft, Munich and Berlin,Germany, va corporation of `Germany Application November 30, 1951,Serial No. 259,076 In JGermany December 13, 1950 (Cl. S-49) -6 Claims..1

This invention is concerned with :a .telephone switching mechanism, :and`particular-ly with a motor for driving it.

The particular 'switching mechanism Ato Awhich the invention relates isofthe class :requiring a motor having sets 'of contacts controlled bythe motor armature for alternately switching in the field or stator'coils Lto :obtain step-by-.step rota-- tion of the motor shaft' andthereby correspond- 4ing rotation of the switching elements, e. rg., oithe wipers, `of fa :switching .device .geared to the motor shaft. Anexample of such :a motor is shown in Patent No. 2,992,546, dated'Ma'y28, 1935. The operation of the above mentioned contacts, that is, theclosing .as well as the opening thereof, must take .place inpredetermined armature positions. AThe proper operation of such amechanism, e. g., of a selector switch, therefore requires .an accurate:adiustment of the contacts. The adjustment was .heretofore carried outby the use of `special gages.

The intention eliminates the :necessity for special gages byprovidingfor each set of .contacts two adjusting members.A One of .these.adjusting members determines the .beginning and the other thetermination of the `contact operation through the .medium of a cam `onthe motor shaft. The adjustment of the corresponding contact set by thesecond adjusting member does .not alter the functions of the contactposition determined .by the irst adjusting member.

The motor :armature is .provided with an adjusting 'disk having aY--plurality of straight edges, and a stationary motor ,part forms a.straight coacting adjusting surface. The .adjustment of the contacts iscarried out biyhol-ding the motor shaft and therewith the armature and acontactactuating cam on .the .motor :shaft indefinite wangularpositions, by inserting between .the straight edges of the .adjustingdisk 1and the coaoting :stationary `adjusting surface a wedge-shapedmember .for holding the armature against rotation in the criticalVangular `position thereof in which .the cam is in deiinite positionrelative to ythe `contacts controlled thereby.

The adjusting disk on the 'motor shaft .is also employed for determiningthe armature Vpositions in 'which the wipers of the :switch controlledby the motor `are infpredetermined resting or loperating positions,respectively. This Vis-done by placing .the motor armaturein Va .certainyangular position 'in Which'a detent spring engages anotch in a detentratchet to hold `the armature in the angular position corresponding tothe desired operating 'positions oithe Aswitch wipers, The correctposition of 'the detent spring relative to the detent ratchet Visadjusted after determining the correct angular position of the armature.`rlhis phase of the adjustment operations r-therefore also isaccomplished'without the use/of 'special gages.

The vinvention is illustrated in the accompanying drawings, in whichFig. l is a View, partly .in elevation and partly in section, of theparts oi the drive motor lfor a switch of the type mentioned before,which are required :for the understanding of the invention.;

Fig. 2 is a side view with certain parts in .section;

Figs. 3-6 show details in elevational .and Asectional views,respectively; and

Fig. 7 illustrates a circuit.

The .parts shown in Figs. 3-5 are on a :somewhat .smaller scale thanthey appear in Figs. l., 2 and 6.

Num-eral l indicates parts of the stationary mounting frame, which .ismade of nonmagn'etic material. On this frame fare .fastened the -coremembers 2 and 3 of the field .or vstator v:coils of the motor. The frameI also carries the rbearing for the armature shaft I4. `One such bearingis indicated in Fig. 2. Also mounted Xon the frame I are the carriersfor the control contacts 1 and S which are governed .by the cam disk 6.'These contacts govern the alternate switching vin and out of the iieldor stator coils coacting with the cores 2 and Y3. Numeral S (Fig. 16).is a 'Camportion which opens the normally `closed contacts 'I and 8incident to ,passing between the corresponding 'contact springs. The twoVpositions or this cam portion are indicated at `and II.

Disposed Yon the armature shaft 4 is .the pinion Il yhich meshes withthe ldrive wheel (not shown) of the associated switch, for example, aselector switch. The Aswitch has ybeen omitted from the drawings to keepthem simple. Also disposed on the .shaft 4 are the detent ratchet I2 andfour stacks of armature laminations I3 which are separated -by spacersI4 and i5. Finally, the shaft 4 also carries the cam Vdisk 5 foroperating the contacts 1 and 8. The spacer I5 between the second andthird laminated armature stacks is a pentagonal disk having ve straightsides or edges 30-34. These edges are provided for coaction with thewedge-shaped holder member -28 (Fig. l) `to carry out the variousadjustments in 'deiinite angular positions of the armature. The edge)vserves for holding the armature in the angular position which it mustassume in normal position and in Working position, respectively, oftheswitch Wipers, The edges 3 I-Sfl are employed in the adjustment of thecontacts I and 8 which control the field or stator coils. The variousdisks, armature laminations, spacers and the cam are held axiallyagainst the pinion I I, which is press-tted on the shaft '4, by the nutI'G. `The various elements are keyed to the shaft 4 by engagement ofrecessed portions with a flattened surface on the shaft and are thusheld against rotation.

Each'contact pair I and l8 is mounted on a 'carrier which is formed byan adjusting lever or member provided with a handle. The pair of contactsprings 'I is thus mounted on the carrier forming the lever having thehandle II, and the pair of contact springs 8 is similarly mounted on thecarrier forming the leverlike adjusting member having the handle I8.VThe adjusting lever II is pivotally mounted at 20 on the platelikeadjusting member I9 and may be secured in adjusted position by means ofthe screw 2l. The adjusting lever I8 is similarly pivotally mounted onthe coacting platelike adjusting member 22 at 23 and may be secured inposition by the screw 2,4. The platelike adjusting members I9 and 22 arerotatably mounted on the bearing that is, they are angularly, rotatablyadjustable concentric to 4the axis of shaft II. These platelikeadjusting members I9 and 22 may be secured in adjusted position by thescrews 25, 25 and 27.

The plate member I9, which overlies the adjusting lever II, is shown inFig. 5 broken away in order to illustrate the shape of the adjustinglever II and the manner in which it is rotatable about the pivot 2Q. Theadjusting lever i3 carrying the contacts 8 is similarly formed andcoacts in a similar manner with its associated platelike adjustingmember 22.

In order to adjust the contacts, the screws 2i and 24 are rst tightenedso as to connect or couple together the adjusting levers I'i and I3 withthe respective coacting platelike adjusting i members I9 and 22. Withthe screws 25, 25 and 2 loosened, the contact set 8 Ycan now bepivotally moved about the journal 5 by means of the lever I8, since theplatelike adjusting member 22 has been clutched to or coupled with thelever I8 by the screw 25. The contact set t is rotated clockwise to aposition in which the cam t oi the disk 6 is in the positionV I in whichit begins to open the springs forming the contactset 8. The

platelike adjusting member 22 is then in the ad- Y justed positionsecured on the motor frame by tightening the screw 25 which has its headin a recess 32 in the platelike adjusting member i9.

The armature and therewith the cam disk 5 are held during this adjustingoperation in an angular position in which the cam part 9. Vis in theposition I. This holding operation is accomplished by the insertion ofthe wedge-shaped holding member 28 in coaction with one of the bstraight edges of the disk I5.

The motor armature must also assume a deiinite angular position in thenormal and in the resting positions of the switching mechanism operatedby the motor. In this position, and as shown in Fig. 2, the cam 9 of thedisk 5 has opened the contact 3 (see also Fig. 7). Contact 'I is closed.Contact an will'be closed to complete a circuit for the stator coil MI(Figs. 3 and 7) so as to start the motor. The armature now rotates andcontact 8 will be closed so as'to switch in the stator coil M2. opened.Incident to further rotation the contact 'I will be closedV to switch inthe stator coil MI and the contact 8 will be opened to disconnect thecoil M2. This interplay continues.

termined by placing the armaturevand therewith the adjusting disk I5Vinto the angular position shown in Fig. l. The adjusting edge 56 of theThe restingorr normal position of the motor armature is de- 4 example,it may extend at right angles thereto. The armature is held in thisangular adjusting position by inserting the wedge-shaped holder member28 between the adjusting edge 30 and the straight backing surface 29formed on the motor frame I. The detent spring is adjustably mounted onthe frame I and such spring is now manipulated intoengagement with thenotch 36 on the detent ratchet I2, and is then secured in this positionon the motor frame. It is understood of course that the baking surface29 may be provided on a different part, for example, on an extension ofa magnet core such as the core 3.

If the adjusting edge 3&3 of the disk I5 is positioned to extend in aplane parallel to or perpendicular to the axis of symmetry of the statorcoils, which bisects the angle formed by the axes 2' and 3', asdescribed, it is possible to change the direction of rotation (right orleft hand rotation) of the motor without altering the determinedarmature position, simply by loosening the nut I5 and displacing thelaminated armature stacks with their spacers by ninety degrees. Thecorrect angular operating position of the armature results rom theangular position oi the detent ratchet as determined by the setting ofthe detent 35, which remains unaltered irrespective of the angularpositions of the laminated armature stacks for either direction ofrotation.

The angular armature positions in which the contacts I and 3 have to berespectively opened and closed do not correspond with the position ofthe armature, which has been determined by the aid of the adjusting edge30 of the disk I5. The reason resides in the fact that the stator coil,

which is in circuit at the beginning otraV switch- Contact Ti isthereupon ing step of the mechanism, is disconnected aiter one half-stepsubsequent to the switching in of the other stator coil. During thesecond halfstep takes place the disconnection of the second stator coilsubsequent to the re-connection of the rst stator coil, leaving thiscoil alone in circuit at the beginning of the next step of the switch.

The adjusting edges 3 I-Sll are provided on the disk I5 in order to holdthe armature in the posiy tions in which the two contacts I and 8 areopened and closed by the cams on the cam disk 6. The cam 9 (Fig. 6) is,for example, in position I at the time when the armature is angularlypositioned, so that one of the edges Bi-B- as-V sumes the position inwhich the edge 30 is shown in Fig. 1. The armature is then held byinserting the wedgelike holding member 28, and the adjusting lever andcontact carrier I8 is adjusted as described before.

In order to place the cam 9 into the position II, the holder member 28is removed and the armatureis rotated until another edge of the disk I5is in position for the described coaction with the holder member 28. Y

The screw 24 is loosened, and the contact carrier having theadjustinglever I8 canY then be rotated about the pivot point 23. Thispivot point is placed Vso that, incident to the angular displacement ofthe lever I8, the point of contact at the contact springs will movenearly in parallel with the edge ofthe cam when the cam is disk I5 is inthis position parallel to the axis of symmetry of `the eld or statorcoils, which bisects the angle formed by the axes 2 and 3.V

in position I; The adjustment ofthe contact 8k now rotatedcounterclockwise untilV the camV begins to separatethe contact springs.|Ifhe lever I8 carrying `the contacts Bis then secured in ad.-

ju'sted position by tightening the screw 2li;

The contacts 8 are now adjusted so that they always open and close atthe proper moments during the operation of the switch controlled by themotor.

The adjustment of the contacts 'l takes place in two other positions ofthe armature and of the cam 9, which are again determined by means ofthe angular positions of the adjusting disk I5 in cooperation with thewedge-shaped holder 28. In the first of these two armature positions,the cam 9 assumes the position relative to the contact 'I whichcorresponds to the position I incident to the adjustment of the contacts8. The adjustment carried out by the displacement of the platelikeadjusting member I9, which is coupled with or clutched to the adjustinglever I1, is secured by the screw 21, thereby connecting the platelikeadjusting member I9 with the platelike adjusting member 22 which issecured on the motor frame l by the screw 25. This latter screw does notimpede the adjustment of the platelike adjusting member I9 due to therecess 32 formed therein. The second adjustment of the contacts 'I isthen carried out, after loosening the screw 2|, in a further position ofthe cam 9 which corresponds to the position II, and such adjustment issecured by tightening the screws 2| and 26.

We claim:

l. A telephone switching device of the class described comprising adrive motor, said drive motor comprising a stationary frame, a shaftjournalled in said frame, said shaft carrying a control cam and anarmature, a plurality of coil-carrying cores on said frame for magneticcoaction with said armature to rotate said shaft, a plurality of contactsets operable by said cam responsive to rotation thereof for governingthe actuation of said coils, and a device for adjusting the positions ofsaid contact sets relative to the angular positions of said control camto bring about actuation of said contact sets in predetermined angularpositions of said armature, said device comprising a carrier for eachcontact set, a mounting member for each contact set, means for pivotallymounting each carrier on its associated mounting member, means forpivo-tally mounting said mounting members on a common axis, a polygonaladjusting disk carried on said motor shaft, said disk forming aplurality of straight edges, a straight baking surface formed on astationary motor part, and a holder member for insertion between any oneof the straight edges formed by said adjusting disk and said stationarysurface to hold the motor shaft and associated parts including said camand said armature in predetermined angular position for subsequentangular displacement of the respective carrier and mounting members ofsaid contact sets to adjust said contact sets for predeterminedactuation by said cam.

2. The structure dened in claim 1, together with a detent ratchet onsaid motor shaft which is rotatable therewith, a detent spring forcooperation with said detent ratchet and means for adjustably mountingsaid detent spring, one of said straight edges on said polygonaladjusting device determining responsive to insertion of said holdermember the angular position of said armature which corresponds to apredetermined operating position of the switching device controlled bysaid drive moto-r, and means for adjusting in this angular position ofsaid armature said detent spring for coaction with said detent ratchet.

3. In a telephone switch of the class described having a motor includinga shaft carrying an armature which is rotatable responsive toenergization of associated stator coils in circuits including twocontrol contacts, one control contact for the circuit of each statorcoil, a device for adjusting the angular positions of said controlcontacts relative to said armature to secure proper operation of saidstator coils, said device comprising a control cam disposed on saidshaft for governing the actuation of said contacts in different angularpositions of said armature, a pair of adjusting members for each of saidcontacts, means for successively holding said armature in two successivepredetermined angular positions, means for angularly adjusting in one ofsaid positions of said armature concentrically with respect to the axisof said shaft a rst one of the adjusting members of one of said pair ofadjusting members associated with one of said control contacts to placesuch contact into an angular position in which actuation thereof can bestarted by said control cam and fixing such adjusted position of saidrst adjusting member, and means for thereafter angularly adjusting inthe other held position of said armature a second one of said adjustingmembers associated with the same contact eccentrically with respect tothe axis of said shaft to place such contact into an angular position inwhich operation thereof by said control cam is completed withoutaltering the position of said contact effected by the adjustment of saidrst adjusting member.

4. The structure dened in claim 3, comprising means for rotatablymounting said second adjusting member on said nrst adjusting member, andmeans for xing said second adjusting member in the adjusted position.

5. The structure defined in claim 3, comprising means for mounting theassociated contact on said second adjusting member, means for rotatablymounting said second adjusting member on said first adjusting member,means for securing said second adjusting member in adjusted position onsaid first adjusting member, and a handle for said second adjustingmember to carry out adjustment thereof and also 'adjustment of said rstadjusting member.

6. The structure defined in claim 3, wherein said means for holding saidarmature in predetermined positions comprises a polygonal disk having aplurality of straight edges mounted on said motor shaft and rotatabletherewith, a fixed member forming a straight backing surface, and awedge-shaped `auxiliary removable member for insertion in engagementwith said straight surface and selectively with one of said straightedges.

WILLY LOI-IS. FRIEDRICH SOMMER.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 787,292 Hatch Apr. 1l, 1905 1,649,060 Decker Nov. 15, 19271,805,164 Carter May 12, 1931 2,002,546 Muller et al May 28, 19352,202,698 Latta May 28, 1940 2,433,608 Handley Dec. 30, 1947 FOREIGNPATENTS Number Country Date 19,146 Australia of 1929

